Thermal and wear resistant tough alloy

Abstract

This invention relates to the thermal and wear resistant, tough alloy at elevated temperatures. The alloy consists essentially of carbon, chromium, nickel, titanium, aluminium, tungsten, molybdenum, silicon, manganese, cobalt and balance iron, further the alloy includes optionally at least one selected from the group consisting of nitrogen, niobium and tantalum, further the alloy includes optionally at least one selected from the group consisting of nitrogen, niobium and tantalum, further the alloy includes optionally at least one selected from the group consisting of boron and zirconium. The alloy according to this invention are widely utilized to serve as the alloy for build-up weld and for guide shoe used in the hot rolling apparatus for fabricating seamless steel pipe.

Description

FIELD OF THE INVENTION

This invention relates to the thermal and wear resistant, tough alloy at elevated temperatures.

The alloy consists essentially of carbon, chromium, nickel, titanium, aluminium, tungsten, molybdenum, silicon, manganese, cobalt and iron, and the alloy further include optionally nitrogen, and at least one selected from the group consisting of niobium, tantalum and the alloy further include optionally at least one selected from the group consisting of boron, zirconium. The alloys of this invention relate to alloys for many application that can be used for providing the build-up welding and for providing the guide shoe for use a hot rolling apparatus for fabricating seamless steel pipes.

BACKGROUND OF THE INVENTION

Generally, a hot rolling apparatus for fabricating seamless steel pipes comprises a pair of upper and lower tapered rolls of a barrel shape disposed in intersecting relation to each other opposed guide shoes disposed on opposite sides of center axes of the tapered barrel rolls and spearhead shaped plug disposed intermediate the tapered barrel rolls in front thereof. A round billet heated at temperature of 1150.degree. to 1250.degree. C. is supplied to the hot rolling apparatus of the tapered roll type. The round billet in hot pierced at its center by the plug while it is being rotated by the tapered barrel rolls. Thereafter, the pierced billet is rolled repeatedly and formed into a seamless steel pipe. In this case, during the fabrication of the pipe, it assumes an elliptical shape due to compressive force and projective force exerted by the tapered barrel rolls. The guide shoes are arranged 90 degrees circumferentially of each roll in opposed relation to each other so as to control the outer shape and the thickness of the pipe. Therefore, the guide shoes are in contact with the steel pipe heated at elevated temperatures, so that the surface of the guide shoes are held in sliding contact with the rotatingly advancing steel pipes.

As a result, the guide shoes are repeatedly subjected to a rapid heating at elevated temperatures and a rapid cooling by cooling water Further, the guide shoes undergo rolling sliding friction under greater stress load.

The guide shoes conventionally used under such serve conditions are made of a material such as an alloy consisting of 26% by weight of chromium--3% by weight of nickel--the balance iron alloy, 26% by weight of chromium--2% by weight of nickel--the balance iron alloy having thermal and wear resistant steel alloy at elevated temperatures, 1% by weight of carbon--5% by weight of copper--the balance iron alloy and 1% by weight of carbon--15% by weight of chromium--5% by weight of molybdenum--the balance nickel alloy. Some of these alloys affect a yield to fabricate a seamless steel pipe because of insufficient corrosion resistance at elevated temperatures. Scales or steel pieces formed at the surface of the steel pipe heated at elevated temperatures are stuck to the surface of the guide shoes by the heat involved. The stuck scales or steel pieces of the guide shoes give rise to damage to the surface thereby affecting the yield rate of the fabrication of the steel pipe. Also some of conventional alloys cannot withstand a thermal shock due to repeated of local heating and water cooling. As a result, cracks are formed on the surface of the guide shoe, so that subjected to damage.

Further some of these conventional alloys are not sufficient in wear resistance. Guide shoe made of such alloy has a shorter service life.

After an extensive study to provide an alloy which are sufficient in thermal resistance, wear resistance, toughness and hardness for use as guide shoes for a hot rolling apparatus of the tapered roller type for fabricating seamless steel pipe, this invention is achieved.

DISCLOSURE OF THE INVENTION

An object of this invention is to provided alloys having thermal shockproof, thermal and wear resistance, and corrosion resistance at elevated temperatures.

Another object of this invention is to provided such alloys for use as guide shoes for hot rolling apparatus of the tapered roller type for fabricating seamless steel pipe.

The alloy of this invention comprises 0.55 to 1.9 percent by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum, the balance iron and incidental impurity, the alloy including optionally 0.1 to 3% by weight of silicon, 0.1 to 2% by weight of manganese, 1 to 8% by weight of cobalt, the alloy including optionally at least one selected from the group consisting of 0.005 to 0.2% by weight of nitrogen, 0.01 to 1.5% by weight of niobium and tantalum and the alloy including optionally at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

The invention will now be more specifically described.

A thermal and wear resistant, tough alloy according to a first embodiment of this invention consists essentially of 0.65 to 1.9% by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum, the balance iron and incidental impurities, the alloy further including optionally 0.1 to 3% by weight of silicon, 0.1 to 2% by weight of manganese, the alloy further including optionally at least one selected from the group consisting of 0.005 to 0.2% by weight of nitrogen, 0.01 to 1.5% by weight of niobium and tantalum, the alloy further including optionally at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

Furthermore, a thermal and wear resistant, tough alloy according to a second embodiment of this invention consists essentially of 0.65 to 1.9% by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum, 1 to 8% by weight of cobalt, the balance iron and incidental impurities, the alloy further including optionally 0.1 to 3% by weight of silicon, 0.1 to 2% by weight of manganese, the alloy further including optionally at least one selected from the group consisting of 0.005 to 0.2% by weight of nitrogen, 0.01 to 1.5% by weight of niobium and tantalum, and the alloy further including optionally at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

Furthermore a thermal and wear resistant, tough alloy according to third embodiment of this invention consists essentially of 0.7 to 1.9% by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum, 0.1 to 3% by weight of silicon, 0.1 to 2% by weight of manganese, the balance iron and incidental impurities, the alloy further including optionally at least one selected from the group consisting of 0.005 to 0.2% by weight of nitrogen, 0.01 to 1.5% by weight of niobium and tantalum, the alloy further including optionally at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium. Furthermore, a thermal and wear resistant, tough alloy according to a fourth embodiment of this invention consists essentially of 0.65 to 1.9% by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum, 0.1 to 3% by weight of silicon, 0.1 to 2% by weight of manganese, 1 to 8% by weight of cobalt, the balance iron and incidental impurities, the alloy further including optionally at least one selected from the group consisting of 0.005 to 0.2% by weight of nitrogen, 0.01 to 1.5% by weight of niobium and tantalum, the alloy further including optionally at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

THE PREFERRED EMBODIMENTS OF THE INVENTION

The effect of the components of the thermal and wear resistant, tough alloy at elevated temperatures according to the invention and the reason why the component have specified contents will now be described.

Carbon: Carbon is dissolved into an alloy matrix at elevated temperatures. Carbon also reacts with chromium, tungsten, molybdenum, titanium, niobium, tantalum and so on to form carbides such as M.sub.7 C.sub.3, MC and M.sub.23 C.sub.6 so that the resultant alloy is improved in the strength and the hardness. Therefore, carbon content serves to impact an excellent wear resistance to the alloy and also imparts the weldability and the castability to the alloy. When the carbon content is below 0.65% by weight, the alloy fails to have the abovementioned properties. On the other hand, when the carbon content exceeds 1.9% by weight, the resultant alloy has an increased amount of deposition of carbides, and also a particle size of the carbides becomes larger to lower the toughness of the alloy so that the alloy can not withstand a thermal shock due to the rapid heating and cooling. Therefore, it is determined that the carbon content should be 0.7 to 1.9% by weight.

Chromium: Chromium is dissolved into an alloy matrix in parts and the remainder reacts with carbon to form carbides. The resultant alloy is improved in the wear resistance and the hardness at elevated temperatures. Chromium serves to impart the corrosion resistance at elevated temperatures. When chromium content is below 28% by weight, the alloy fails to have the abovementioned properties. When chromium content exceeds 39% by weight, the alloy has a decreased amount of the thermal shock resistance. Therefore, it is determined that chromium content should be 28 to 39% by weight.

Nickel: Nickel is dissolved into an alloy matrix to stabilize austenite matrix and enhance the thermal shock resistance and the toughness. On the other hand, nickel reacts with aluminium and titanium to form an intermetallic compound such as {Ni.sub.3 (Al, Ti)}, furthermore the resultant alloy is improved in the strength and the wear resistance at elevated temperatures similar to chromium. When the nickel content is below 25% by weight, the alloy fails to have the abovementioned properties. When the nickel content exceeds 49% by weight, the alloy fails to have more improved properties. Therefore, it is determined that nickel content should be 25 to 49% by weight in view of economical use.

Titanium: Titanium not only suppresses a growth of a crystal grain in the alloy matrix but atomize preferably the crystal grain. Titanium reacts with carbon and nitrogen to form MC type carbide and nitride, further reacts with nickel and aluminium to form the intermetallic compound such as abovementioned {Ni.sub.3 (Al, Ti)}. The resultant alloy is improved in the strength and the wear resistance at elevated temperatures. When the titanium content is below 0.01% by weight, the alloy fails to have the abovementioned properties. When the titanium content exceeds 4.5% by weight, the resultant alloy is deteriorated in the toughness of the alloy due to accelerate the formation of carbide at elevated temperatures and further deteriorated the corrosion resistance at elevated temperature due to proceed remarkably the formation oxide at elevated temperatures. Therefore, it is determined that the titanium content should be 0.01 to 3.5% by weight.

Aluminium: The alloy is improved by the addition of aluminium the oxidation resistance and the corrosion resistance at elevated temperatures in the coexistence of chromium. As abovementioned, aluminium reacts with nickel and titanium to from the intermetallic compound such as {Ni.sub.3 (Al, Ti)} and further reacts with nitrogen to form nitride. The resultant is improved in the strength and the wear resistance at elevated temperatures and improved in the thermal shock resistance and the toughness.

When the aluminium content is below 0.01% by weight, the alloy fails to have the abovementioned properties. When the aluminium content exceeds 4.5% by weight, the resultant alloy shows the decrease of the fluidity and the castability in the melt, as a result, the resultant alloy not only becomes difficulty the production in the casting but cannot make use of the production in practice because of the deterioration of the toughness and the weldability. Therefore, it is determined that the aluminium content should be 0.01 to 4.5% by weight, furthermore preferably, 0.01 to 3.5% by weight.

Tungsten: Tungsten is dissolved into an alloy matrix. Tungsten also reacts with carbon to form a carbide. The resultant alloy is improved in the hardness and the wear resistance at elevated temperatures. When tungsten content is below 0.1% by weight, the resultant alloy fails to have the abovementioned properties. When the tungsten content exceeds 8% by weight, the resultant alloy is improved the wear resistance, but also is deteriorated the toughness and the thermal shock. Therefore, it is determined that the tungsten content should be 0.1 to 8% by weight, furthermore preferably 0.5 to 8% by weight.

Molybdenum: The alloy is improved by the addition of molybdenum the wear resistance at elevated temperatures similar to tungsten component.

When molybdenum content is below 0.1% by weight, the resultant alloy fails to have the abovementioned properties. When the molybdenum content exceeds 9% by weight, the resultant alloy is deteriorated the toughness and the thermal shock resistance. Therefore, it is determined that the molybdenum content should be 0.1 to 9% by weight, furthermore preferably 0.5 to 9% by weight.

Silicon: The alloy is improved by the addition of silicon the thermal resistance, the deoxidation effect and the fluidity of the melt similar to chromium. The resistant alloy is improved in the castability and the strength at elevated temperatures.

When the silicon content is below 0.1% by weight, the resultant alloy fails to have the abovementioned properties. When the silicon content exceeds 3% by weight, the resultant alloy is deteriorated the toughness and the weldability in the relation of chromium component. Therefore, it is determined that the silicon content should be 0.1 to 3% by weight. When silicon is used as the deoxidation agent, however, silicon includes below 0.1% by weight of th incidental impurities. It is suitable in this case that the silicon included with the incidental impurities is added over 0.1% by weight.

Manganese: Manganese is dissolved into the alloy matrix to stabilize the austenite matrix. The resultant alloy is improved in the thermal shock resistance and the wear resistance at elevated temperatures and the effect of the deoxidation.

When the manganese content is below 0.1% weight, the resultant alloy fails to have the abovementioned properties. When the manganese content exceeds 2% by weight, the resultant alloy is deteriorated the corrosion resistance at elevated temperatures. Therefore, it is determined that the manganese content should be 0.1 to 2% by weight. Manganese component similar to silicon component includes below 0.1% by weight of the incidental impurities. It is suitable in this case that the manganese included with the incidental impurities is added over 0.1% by weight.

Cobalt: Cobalt is dissolved into the austenite matrix to improve the strength at elevated temperatures. The resultant alloy is improved in the wear resistance and the thermal shock resistance at elevated temperatures. When the cobalt content is below 1% by weight, the resultant alloy fails to have the abovementioned properties. When the cobalt content exceeds 8% by weight, the resultant alloy does not show more effective improvement but rather than shows the decrease of the abovementioned properties. Therefore, it is determined that the cobalt content should be 1 to 8% by weight.

Nitrogen: Nitrogen is dissolved into the austenite matrix to stabilize the alloy. Nitrogen also reacts with a metal component to form the nitride of the metal. The resultant alloy is improved in the strength at elevated temperatures. When the resultant alloy is required to have the strength at elevated temperatures, the nitrogen component is included optionally in the alloy. When the nitrogen content is below 0.005% by weight, the resultant alloy does not improve in more effective strength at elevated temperatures. When the nitrogen content exceeds 0.2% by weight, the resultant alloy not only has an increased amount of nitride but has a gross particle of the nitride. The resultant alloy is a brittle alloy and is deteriorated in the thermal shock resistance. Therefore, it is determined that the nitrogen content should be 0.005 to 0.2% by weight.

Niobium and tantalum: The alloy is suppressed by the addition of these component specially to the growth of the crystal in the alloy matrix. These component also react with carbon and nitrogen to form the MC type carbide and the nitride. The resultant alloy is improved in the strength and the wear resistance at elevated temperatures, also improved more homogenized action. When the resultant alloy is required to have the abovementioned properties, niobium and tantalum is added optionally into the alloy. When niobium and tantalum content are below 0.01% by weight, the resultant alloy fails to have the abovementioned properties. When niobium and tantalum content exceed 1.5% by weight, the resistant alloy is deteriorated in the corrosion resistance due to increase the growth of the oxide at elevated temperatures and furthermore deteriorated the toughness and the wear resistance due to increase extraordinarily the formation of the carbide. Therefore, it is determined that niobium and tantalum content should be 0.01 to 1.5% by weight.

Boron and zirconium: The alloy is improved by the addition of these component the homogenized action and the strength, the wear resistance, the thermal shock resistance and the corrosion resistant at elevated temperatures. When boron and zirconium contents are below 0.001% by weight, the resultant alloy fail to have the abovementioned properties. When boron and zirconium contents exceed 0.2% by weight, the resultant alloy is deteriorated in the toughness, the thermal shock resistance, the castability and the weldability. Therefore, it is determined that boron and zirconium content should be 0.001 to 0.2% by weight.

Iron: Iron is included as the remainder in the alloy of this invention. Iron has the properties similar to nickel component. Iron is added as the alternative to the expensive nickel component in view of the reduction of the cost.

Each metal components are weighted and heated by the usual high frequency melting furnace under atmospheric pressure at 1400.degree. to 1700.degree. C. for 20 to 30 min. to form the melt. The melt is casted into the sand mold and the casted alloy is prepared each of the test piece for the test. These test piece are used for the many test, such as the hardness, the impact resistance at room temperature, the thermal shock resistance and the wear resistance. The thermal shock resistance test is carried out by the repetition of the rapid heating and the rapid cooling under nearly conditions of the practical machine.

The hardness test is carried out by the measurement of Vickers hardness at room temperature, at 900.degree. C. and at 1000.degree. C. The Ohgoshi type intermetallic wear resistance test is carried out under the load of 18.2 kg, the wear velocity of 0.083 m/sec. at room temperature in the dry condition. The opposited metal having over 57 of Rockwell hardness (H.sub.R C) of the metal such as SUJ-2 is used in this test. The amount of the specific wear is estimated by the measurement of the wear resistance to the test piece. Furthermore, the test piece used for thermal shock resistance test is prepared to form in rectangular pillar shape of 12 mm.times.12 mm.times.30 mm having the recess of the spherical surface at the center of the pillar end. The thermal shock test comprises to repeating a cycle which the test piece is heated by oxygen-propane gas burner to hold at about 900.degree. C. at the recess of the spherical surface for 30 sec. and thereafter are cooled at once by blowing off with the water spray to hold at about 200.degree. C. at the recess of the spherical surface. This cycle are carried out repeatedly and at every three time the test piece is observed the detection of the crack by the fluorescence permeation at the recess of the spherical surface and measured the occurrence of the crack. If the number of the cycle which the crack occurred at the test piece is over 30, the notation of the thermal shock resistance refers to >30 in the TABLE as follows. In other words, it is meant that the notation of >30 does not are observed the occurrence of the crack at the recess of the spherical surface till the repetition of thermal shock resistance test of 30 times.

The composition and the properties of comparative alloy are showed to compare with the thermal and resistant, tough alloy at elevated temperatures according to this invention in the TABLE. The content of the component put on asteristic sign at the shoulder of the numeral in comparative alloy are showed to have a different composition content from the scope of the alloy according to this invention. Furthermore, the alloy of prior art are showed in the relation with the alloy of this invention. The percentage of content refers to the percentage by weight as follow.

EXAMPLE 1

C-Cr-Ni-Ti-Al-W-Mo-Fe ALLOY

As are shown in TABLE 1-1, TABLE 1-2, TABLE 1-3, and TABLE 1-4, each metal component is weighted, added to mixing, and heated by the usual high frequency melting furnace under the atmosphere to form the melt and thereafter the melt is casted into the sand mold to prepare the casting.

The composition of Nos. 1 to 16 show C-Cr-Ni-Ti-Al-W-Mo-Fc base alloy according to this invention. Furthermore, Nos. 17 to 19 show the abovementioned alloy included silicon and Nos. 22 to 22 show the alloy included manganese and Nos. 23 to 25 show the alloy included nitrogen. Nos. 26 to 61 also show the abovementioned alloy including optionally at least one selected from the group consisting of silicon, manganese, nitrogen, niobium, tantalum, boron and zirconium.

The comparative alloy of Nos. 62 to 70 show to include the content of the composition that the content were without the scope of this invention according to C-Cr-Ni-Ti-Al-W-Mo-Fe alloy.

As are shown in TABLE 2-1, TABLE 2-2, and TABLE 2-3, the results of the properties of the alloy is shown each Vickers hardness at room temperature, at 900.degree. C., and at 1000.degree. C., furthermore Charpy impact strength at room temperature, the amount of the specific wear, and the number of the cycle till the occurrence of the crack.

No. 6 in TABLE 1 consists essentially of 0.79% by weight of carbon, 30.25% of chromium, 25.2% of nickel, 1.79% of titanium, 1.02% of aluminium, 5.36% of tungsten, 3.31% of molybdenum and the balance iron (% refers to percent by weight). The properties of No. 6 alloy is shown in TABLE 2-1. For example, No. 6 alloy show 332 of Vickers hardness at room temperature, 151 at 900.degree. C., 145 at 1000.degree. C., and 1.34 kg-m/cm.sup.2 of Charpy impact strength, 1.98.times.10.sup.-7 of the amount of the specific wear, >30 of the number of the cycle till the occurrence of the crack.

The comparative alloy of No. 62 consists essentially of 0.49% by weight of carbon, 35.06% of chromium, 30.11% of nickel, 0.59% of titanium, 0.13% of aluminium, 5.60% of tungsten, 4.92% of molybdenum and the balance iron (% refers to percent by weight). This No. 62 showed >30 as the number of the cycle till the occurrence of the crack in TABLE 2-3. The No. 62 also is shown 3.71.times.10.sup.-7 of the amount of the specific wear, 0.87 kg-m/cm.sup.2 of Charpy impact strength at room temperature, 239 of Vickers hardness at room temperature, 95 at 900.degree. C., and 80 at 1000.degree. C.

The prior art alloy No. 71 consists essentially of 1.32% by weight of carbon, 25.89% of chromium, 11.04% of nickel, 0.50% of molybdenum, 1.59% of silicon, 2.00% of manganese, 0.18% of vanadium and the balance iron (% refers to percent by weight). This No. 71 alloy is shown 3.28.times.10.sup.-7 of the amount of the specific ear, 0.89 kg-m/cm.sup.2 Charpy impact strength at room temperature, 259 of Vickers hardness at room temperature, 77 at 900.degree. C., and 64 at 1000.degree. C.

These alloys are shown the content of the composition and the properties of the alloy in TABLE 1-1, TABLE 1-2, TABLE 1-3, TABLE 1-4 and TABLE 2-1, TABLE 2-2, TABLE 2-3, respectively.

TABLE 1__________________________________________________________________________ COMPONENT OF COMPOSITION (% by weight) C Cr Ni Ti Al W Mo Si Mn N Nb Ta B Zr Fe__________________________________________________________________________ALLOY OF THISINVENTION1 0.561 35.04 30.10 0.60 0.12 5.57 4.90 -- -- -- -- -- -- -- bal.2 1.16 35.02 30.08 0.58 0.11 5.56 4.91 -- -- -- -- -- -- -- bal.3 1.88 35.01 30.12 0.57 0.11 5.59 4.88 -- -- -- -- -- -- -- bal.4 0.75 28.4 30.22 0.32 0.03 5.04 4.79 -- -- -- -- -- -- -- bal.5 0.74 38.5 30.24 0.30 0.04 5.01 4.80 -- -- -- -- -- - -- bal.6 0.79 30.25 25.2 1.79 1.02 5.36 3.31 -- -- -- -- -- -- -- bal.7 0.80 30.24 48.6 1.78 1.05 5.34 3.30 -- -- -- -- -- -- -- bal.8 0.83 30.06 44.60 0.011 4.104 4.98 2.98 -- -- -- -- -- -- -- bal.9 0.82 30.02 44.61 4.48 0.016 4.96 2.94 -- -- -- -- -- -- -- bal.10 0.85 30.04 47.05 4.107 0.012 4.95 2.92 -- -- -- -- -- -- -- bal.11 0.85 30.06 47.07 1.89 2.46 4.93 2.94 -- -- -- -- -- -- -- bal.12 0.83 30.03 47.04 0.013 4.48 4.94 2.90 -- -- -- -- -- -- -- bal.13 1.02 35.08 35.10 0.70 0.11 0.13 7.95 -- -- -- -- -- -- -- bal.14 1.01 35.07 35.09 0.66 0.11 7.91 2.12 -- -- -- -- -- -- -- bal.15 1.04 35.09 35.07 0.68 0.13 7.16 0.11 -- -- -- -- -- -- -- bal.16 1.03 35.08 35.09 0.65 0.10 1.99 8.93 -- -- -- -- -- -- -- bal.17 1.06 31.56 40.10 1.52 0.03 2.04 5.11 0.13 -- -- -- -- -- -- bal.18 1.02 31.55 40.07 1.51 0.05 2.06 5.13 1.51 -- -- -- -- -- -- bal.19 1.04 31.59 40.09 1.49 0.03 2.02 5.10 2.93 -- -- -- -- -- -- bal.20 0.81 31.61 35.11 1.54 0.07 2.99 6.07 -- 0.12 -- -- -- -- -- bal.21 0.80 31.62 35.13 1.55 0.05 2.96 6.06 -- 0.87 -- -- -- -- -- bal.22 0.80 31.60 35.10 1.52 0.06 2.94 6.04 -- 1.94 -- -- -- -- -- bal.23 0.82 31.50 35.11 1.51 0.12 3.05 6.04 -- -- 0.0055 -- -- -- -- bal.24 0.80 31.49 35.13 1.47 0.09 3.01 6.00 -- -- 0.016 -- -- -- -- bal.25 0.78 31.47 35.10 1.46 0.10 3.00 6.01 -- -- 0.197 -- -- -- -- bal.26 0.79 31.50 35.13 1.48 0.06 3.04 6.02 0.80 -- 0.015 -- -- -- -- bal.27 0.80 31.51 35.10 1.50 0.05 3.01 6.00 -- 0.83 0.016 -- -- -- -- bal.28 0.81 31.57 35.12 1.51 0.26 3.02 6.04 -- -- -- 0.012 -- -- -- bal.29 0.80 31.56 35.11 1.50 0.24 3.01 6.02 -- -- -- 1.04 -- -- -- bal.30 0.78 31.56 35.12 1.51 0.22 3.01 6.01 -- -- -- 1.48 -- -- -- bal.31 0.80 31.54 35.13 1.54 0.26 3.02 6.03 -- -- -- -- 0.013 -- -- bal.32 0.83 31.52 35.15 1.52 0.24 3.01 6.02 -- -- -- -- 1.02 -- -- bal.33 0.81 31.50 35.12 1.50 0.24 3.00 6.04 -- -- -- -- 1.45 -- -- bal.34 0.78 31.55 35.14 1.51 0.25 3.03 6.01 -- -- -- 0.43 0.52 -- -- bal.35 0.81 31.56 35.20 1.48 0.07 2.98 6.01 0.46 -- -- 0.72 -- -- -- bal.36 0.80 31.53 35.17 1.50 0.05 2.99 6.03 0.42 -- -- -- 0.85 -- -- bal.37 0.81 31.54 35.21 1.49 0.06 2.97 6.05 -- 0.50 -- 0.64 -- -- -- bal.38 0.80 31.52 35.22 1.50 0.05 2.97 6.02 -- 0.51 -- -- 0.86 -- -- bal.39 0.79 31.52 35.20 1.48 0.06 2.95 6.01 0.45 -- -- 0.70 0.81 -- -- bal.40 0.80 31.51 35.21 1.50 0.32 2.96 6.02 -- -- -- -- -- 0.0013 -- bal.41 0.79 31.54 35.23 1.51 0.31 2.98 6.00 -- -- -- -- -- 0.099 -- bal.42 0.81 31.50 35.21 1.48 0.29 2.96 5.99 -- -- -- -- -- 0.196 -- bal.43 0.79 31.54 35.25 1.50 0.32 2.98 6.05 -- -- -- -- -- -- 0.0011 bal.44 0.79 31.51 35.23 1.48 0.32 2.97 6.04 -- -- -- -- -- -- 0.094 bal.45 0.78 31.50 35.24 1.46 0.30 2.97 6.00 -- -- -- -- -- -- 0.197 bal.46 0.79 31.52 35.22 1.48 0.31 2.99 6.01 -- -- -- -- -- 0.041 0.031 bal.47 0.83 31.46 35.21 1.45 0.12 2.98 6.01 0.75 -- -- -- -- 0.0016 -- bal.48 0.81 31.50 35.23 1.47 0.14 2.99 6.00 -- 0.72 -- -- -- -- 0.0014 bal.49 0.80 31.51 35.24 1.48 0.11 2.98 6.01 -- 0.70 -- -- -- 0.0013 0.0017 bal.50 0.78 31.49 35.21 1.50 0.36 3.00 6.01 -- -- 0.102 0.83 -- -- -- bal.51 0.79 31.50 35.22 1.48 0.34 3.01 6.02 -- -- 0.105 -- -- 0.005 -- bal.52 0.77 31.51 35.24 1.47 0.33 3.02 6.00 -- -- -- -- 1.07 -- 0.0028 bal.53 0.78 31.50 35.22 1.49 0.10 3.00 6.02 0.70 -- 0.013 -- 1.09 -- -- bal.54 0.79 31.49 35.26 1.46 0.09 3.01 6.00 0.72 -- 0.007 -- -- -- 0.096 bal.55 0.79 31.51 35.21 1.48 0.11 3.04 6.01 0.70 -- -- 0.015 -- 0.104 -- bal.56 0.78 31.48 35.27 1.46 0.10 2.99 6.00 -- 0.81 0.006 -- 0.61 -- -- bal.57 0.77 31.54 35.28 1.44 0.09 3.03 6.01 -- 0.79 0.009 -- -- -- 0.0095 bal.58 0.79 31.50 35.24 1.48 0.10 3.04 5.98 -- 0.76 -- 1.10 -- 0.0060 0.0029 bal.59 0.83 31.50 35.27 1.49 0.08 3.00 6.01 -- -- 0.007 0.05 0.18 -- 0.0022 bal.60 0.82 31.52 35.26 1.47 0.07 3.01 6.02 -- 0.36 0.007 -- 0.30 0.0013 0.0014 bal.61 0.81 31.51 35.24 1.48 0.09 3.02 6.04 0.25 -- 0.009 0.16 0.08 0.0016 0.0012 bal.COMPARATIVEALLOY62 0.49* 35.06 30.11 0.59 0.13 5.60 4.92 -- -- -- -- -- -- -- bal.63 2.21* 35.04 30.10 0.56 0.10 5.57 4.89 -- -- -- -- -- -- -- bal.64 0.76 26.4* 30.24 0.33 0.04 5.06 4.78 -- -- -- -- -- -- -- bal.65 0.75 41.3* 30.21 0.31 0.02 5.00 4.82 -- -- -- -- -- -- -- bal.66 0.80 30.27 24.1* 1.82 1.01 5.40 3.34 -- -- -- -- -- -- -- bal.67 0.83 30.04 44.63 5.01* 0.013 4.98 2.96 -- -- -- -- -- -- -- bal.68 0.84 30.05 47.02 0.011 5.00* 4.96 2.93 -- -- -- -- -- -- -- bal.69 1.03 35.09 35.06 0.68 0.13 9.14* 2.14 -- -- -- -- -- -- -- bal.70 1.01 35.07 35.10 0.66 0.11 1.97 9.86* -- -- -- -- -- -- -- bal.prior art alloy71 1.32 25.89 11.04 -- -- -- 0.50 1.59 2.00 -- -- -- -- V:0.18 bal.72 1.28 33.92 bal. -- -- 3.06 2.98 0.83 0.76 -- -- -- -- Cu:4.49 17.89__________________________________________________________________________ TABLE 2______________________________________VICKERS CharpyHARDNESS impact Amount of Number ofat strength specific cycle tillroom 900.degree. 1000.degree. at room temp wear .times. occurrencetemp. C. C. kg-m/cm.sup.2 10.sup.-7 of crack______________________________________ALLOY OF THIS INVENTION 1 317 158 146 1.79 1.99 >30 2 329 167 150 1.71 1.82 >30 3 377 246 188 1.13 1.26 24 4 328 166 149 1.89 1.78 >30 5 354 180 176 1.58 1.40 >30 6 332 151 145 1.34 1.98 >30 7 356 218 174 2.17 1.70 >30 8 335 216 161 1.98 1.51 27 9 368 248 187 1.06 1.00 2110 356 243 185 1.69 1.41 2711 367 251 192 1.57 1.28 2412 385 265 210 1.00 0.99 2113 374 228 177 1.18 1.35 3014 391 256 205 1.12 0.92 2415 378 250 186 1.39 1.26 3016 399 259 208 1.16 0.97 2117 366 227 175 1.47 1.66 >3018 371 234 179 1.38 1.55 >3019 382 249 181 1.26 1.39 3020 361 234 142 1.89 1.82 >3021 356 232 141 1.91 1.79 >3022 354 229 139 1.99 1.68 >3023 357 235 140 1.87 1.64 >3024 364 241 150 1.69 1.46 2725 369 248 164 1.00 1.31 2126 361 244 151 1.59 1.43 3027 359 243 147 1.61 1.40 >3028 357 234 141 1.88 1.67 >3029 361 238 143 1.62 1.60 >3030 374 249 152 1.47 1.30 3031 357 235 141 1.98 1.67 >3032 361 239 146 1.67 1.50 >3033 376 251 155 1.38 1.27 3034 363 241 144 1.69 1.59 >3035 362 239 141 1.66 1.51 >3036 361 240 142 1.69 1.48 >3037 359 239 141 1.70 1.57 >3038 361 241 144 1.72 1.52 >3039 363 242 145 1.70 1.46 >3040 357 233 141 1.86 1.61 >3041 361 238 145 1.82 1.59 >3042 368 249 153 1.01 1.21 2443 357 232 139 1.90 1.63 >3044 361 239 146 1.68 1.52 2745 368 250 153 1.00 1.18 2146 361 238 142 1.77 1.40 >3047 360 236 140 1.92 1.60 >3048 358 234 139 1.93 1.61 >3049 361 238 143 1.87 1.56 >3050 365 245 150 1.48 1.25 2151 368 247 152 1.27 1.18 2152 361 236 143 1.79 1.50 >3053 364 241 146 1.68 1.41 3054 360 237 141 1.66 1.49 >3055 365 241 143 1.72 1.32 3056 358 237 139 1.84 1.51 >3057 360 239 141 1.82 1.50 >3058 361 240 143 1.83 1.48 >3059 362 241 146 1.80 1.44 >3060 372 246 153 1.88 1.16 >3061 375 251 155 1.90 1.10 >30comparative alloy62 239 95 80 0.87 3.71 >3063 422 274 220 0.46 0.70 964 263 97 86 1.87 2.56 >3065 392 216 191 0.66 1.15 666 283 127 121 0.49 2.72 >3067 425 282 220 0.36 0.77 668 438 293 245 0.27 0.61 369 409 268 214 0.31 0.70 670 415 272 217 0.25 0.68 3prior art alloy71 259 77 64 0.89 3.28 1872 305 143 130 0.43 1.97 3______________________________________

EXAMPLE 2

C-Cr-Ni-Co-Ti-Al-W-Mo-Fe ALLOY

The thermal and wear resistant, tough at elevated temperatures alloy in this invention are shown in EXAMPLE 2. The alloy is different from the content of the composition that the cobalt included one to 8% by weight in comparison with the alloy of EXAMPLE 1.

Alloys of Nos. 73 to 134 according to this invention, the comparative alloys of Nos. 135 to 144 and the prior art alloys of Nos. 145 to 146 are shown in TABLE 3-1, TABLE 3-2, TABLE 3-3 and TABLE 3-4 respectively. Furthermore similar to EXAMPLE 1, the properties of these alloys are shown in TABLE 4-1, TABLE 4-2, TABLE 4-3, respectively. No. 78 alloy in TABLE 3-1 consists essentially of 0.77% by weight of carbon, 30.23% chromium, 25.9% of nickel, 1.61% of cobalt, 1.80% of titanium, 1.00% of aluminium, 5.37% of tungsten, 3.26% of molybdenum and the balance iron (% refers to percent by weight). No. 78 alloy is shown 337 of Vickers hardness at room temperature, 154 at 900.degree. C., and 148 at 1000.degree. C. in TABLE 4-1. No. 78 alloy also is shown 1.37 kg-m/cm.sup.2 of Charpy impact strength at room temperature, 1.93.times.10.sup.-7 of the amount of the specific wear, >30 of the number of the cycle till the occurrence of the crack. No. 78 alloy is improved in the hardness, the wear resistance at elevated temperatures due to include the content of cobalt in comparison with No. 6 of EXAMPLE 1.

In the comparison with comparative alloys (Nos. 133 to 144) and prior art alloys (Nos. 145 to 146), for example, No. 78 alloy of this invention is shown >30 of the number of the cycle till the occurrence of the crack, 148 of Vickers hardness at 1000.degree. C., on other hand No. 145 alloy of prior art showed 18 of the number of the cycle till the occurrence of the crack.

The scope of the composition in this invention and its properties showed in TABLE 3-1, TABLE 3-2, TABLE 3-3, TABLE 3-4 and TABLE 4-1, TABLE 4-2, TABLE 4-3, respectively.

TABLE 3__________________________________________________________________________ COMPONENT OF COMPOSITION (% by weight) C Cr Ni Co Ti Al W Mo Si Mn N Nb Ta B Zr Fe__________________________________________________________________________Alloythis invention73 0.557 35.07 30.09 5.04 0.54 0.11 5.60 4.91 -- -- -- -- -- -- -- bal.74 1.23 35.03 30.10 5.01 0.52 0.07 5.59 4.88 -- -- -- -- -- -- -- bal.75 1.86 35.02 30.11 5.09 0.50 0.10 5.61 4.77 -- -- -- -- -- -- -- bal.76 0.74 28.6 30.20 2.17 0.31 0.04 5.02 4.78 -- -- -- -- -- -- -- bal.77 0.72 38.2 30.21 2.19 0.26 0.02 4.96 4.74 -- -- -- -- -- -- -- bal.78 0.77 30.23 25.9 1.61 1.80 1.00 5.37 3.26 -- -- -- -- -- -- -- bal.79 0.79 30.25 48.1 1.60 1.76 1.07 5.32 3.24 -- -- -- -- -- -- -- bal.80 1.04 31.48 30.30 1.1 0.62 0.11 5.10 3.03 -- -- -- -- -- -- -- bal.81 1.02 31.46 30.29 7.9 0.61 0.10 5.11 3.01 -- -- -- -- -- -- -- bal.82 0.81 30.08 44.58 1.49 0.013 4.092 4.96 2.96 -- -- -- -- -- -- -- bal.83 0.80 30.01 44.59 1.47 4.491 0.0014 4.94 2.92 -- -- -- -- -- -- -- bal.84 0.84 30.03 47.04 1.50 4.106 0.012 4.92 2.90 -- -- -- -- -- -- -- bal.85 0.82 30.05 47.06 1.53 0.011 4.489 4.90 2.91 -- -- -- -- -- -- -- bal.86 1.04 35.10 35.07 5.09 0.64 0.12 0.14 7.96 -- -- -- -- -- -- -- bal.87 1.00 35.08 35.04 5.06 0.62 0.10 7.98 2.10 -- -- -- -- -- -- -- bal.88 1.05 35.07 35.06 5.01 0.65 0.11 7.14 0.12 -- -- -- -- -- -- -- bal.89 1.02 35.01 35.01 5.03 0.63 0.09 2.01 8.89 -- -- -- -- -- -- -- bal.90 1.05 31.53 40.08 5.06 1.50 0.04 2.10 5.09 0.12 -- -- -- -- -- -- bal.91 1.01 31.54 40.04 5.08 1.51 0.06 2.11 5.07 1.53 -- -- -- -- -- -- bal.92 1.02 31.58 40.07 5.10 1.47 0.03 2.09 5.03 2.96 -- -- -- -- -- -- bal.93 0.80 31.59 35.10 2.01 1.52 0.08 2.98 6.10 -- 0.15 -- -- -- -- -- bal.94 0.81 31.56 35.11 2.04 1.50 0.05 2.96 6.09 -- 0.96 -- -- -- -- -- bal.95 0.79 31.54 35.09 2.02 1.51 0.07 2.98 6.07 -- 1.97 -- -- -- -- -- bal.96 0.81 31.48 35.09 2.10 1.50 0.11 3.02 6.02 -- -- 0.0052 -- -- -- -- bal.97 0.80 31.50 35.07 2.09 1.48 0.10 3.00 6.01 -- -- 0.103 -- -- -- -- bal.98 0.79 31.49 35.06 2.07 1.46 0.11 3.01 6.02 -- -- 0.196 -- -- -- -- bal.99 0.81 31.52 35.10 2.09 1.50 0.05 3.03 6.00 0.79 -- 0.014 -- -- - -- bal.100 0.83 31.50 35.09 2.07 1.49 0.06 3.02 6.01 -- 0.83 0.016 -- -- -- -- bal.101 0.80 31.53 35.10 2.04 1.53 0.24 3.06 6.04 -- -- -- 0.012 -- -- -- bal.102 0.79 51.54 35.08 2.02 1.54 0.23 3.04 6.01 -- -- -- 1.03 -- -- -- bal.103 0.77 31.50 35.09 2.04 1.50 0.23 3.03 6.00 -- -- -- 1.46 -- -- -- bal.104 0.81 31.52 35.10 2.01 1.53 0.25 3.04 6.02 -- -- -- -- 0.011 -- -- bal.105 0.82 31.51 35.09 2.03 1.52 0.23 3.02 6.04 -- -- -- -- 0.96 -- -- bal.106 0.80 31.50 35.07 2.01 1.52 0.24 3.01 6.03 -- -- -- -- 1.46 -- -- bal.107 0.79 31.53 35.09 2.04 1.51 0.26 3.03 6.00 -- -- -- 0.61 0.34 -- -- bal.108 0.80 31.55 35.10 2.02 1.49 0.06 2.99 6.00 0.43 -- -- 0.70 -- -- -- bal.109 0.81 31.54 35.11 2.04 1.50 0.07 2.98 6.01 0.40 -- -- -- 0.84 -- -- bal.110 0.80 31.52 35.10 2.01 1.48 0.08 2.99 6.04 -- 0.51 -- 0.67 -- -- -- bal.111 0.79 31.54 35.13 2.03 1.51 0.09 2.97 6.02 -- 0.53 -- -- 0.85 -- -- bal.112 0.78 31.51 35.12 2.00 1.49 0.07 2.96 6.00 0.42 -- -- 0.71 0.83 -- -- bal.113 0.81 31.50 35.08 2.02 1.49 0.31 2.96 6.03 -- -- -- -- -- 0.0012 -- bal.114 0.80 31.52 35.10 2.01 1.47 0.30 2.96 6.01 -- -- -- -- -- 0.096 -- bal.115 0.80 31.49 35.09 2.00 1.48 0.30 2.95 6.02 -- -- -- -- -- 0.192 -- bal.116 0.79 31.51 35.10 2.01 1.49 0.32 2.97 6.04 -- -- -- -- -- -- 0.0013 bal.117 0.77 31.52 35.09 2.03 1.47 0.31 2.98 6.03 -- -- -- -- -- -- 0.103 bal.118 0.78 31.50 35.06 2.00 1.48 0.30 2.97 6.01 -- -- -- -- -- -- 0.196 bal.119 0.79 31.51 35.07 2.02 1.47 0.32 2.98 6.00 -- -- -- -- -- 0.039 0.028 bal.120 0.82 31.49 35.08 2.00 1.46 0.11 2.96 5.99 0.72 -- -- -- -- 0.0014 -- bal.121 0.80 31.47 35.07 2.01 1.47 0.13 2.98 6.02 -- 0.70 -- -- -- -- 0.0015 bal.122 0.81 31.48 35.09 2.04 1.45 0.10 2.99 6.01 -- 0.69 -- -- -- 0.0016 0.0013 bal.123 0.79 31.50 35.10 2.02 1.47 0.34 3.02 6.00 -- -- 0.106 0.80 -- -- -- bal.124 0.77 31.49 35.09 2.03 1.49 0.33 3.00 6.02 -- -- 0.103 -- -- 0.006 -- bal.125 0.78 31.47 35.07 2.04 1.46 0.30 3.01 6.00 -- -- -- -- 1.00 -- 0.0026 bal.126 0.77 31.50 35.06 2.03 1.46 0.09 3.04 5.99 0.70 -- 0.010 -- 1.03 -- -- bal.127 0.79 31.51 35.07 2.06 1.47 0.08 3.02 5.98 0.68 -- 0.009 -- -- -- 0.094 bal.128 0.78 31.49 35.04 2.02 1.48 0.09 3.05 6.00 0.69 -- -- 0.018 -- 0.102 -- bal.129 0.79 31.48 35.06 2.05 1.45 0.11 3.00 5.99 -- 0.76 0.007 -- 0.56 -- -- bal.130 0.80 31.50 35.10 2.03 1.43 0.10 2.99 6.01 -- 0.77 0.008 -- -- -- 0.0094 bal.131 0.78 31.47 35.09 2.04 1.44 0.13 2.98 5.99 -- 0.80 -- 1.02 -- 0.0051 0.0033 bal.132 0.81 31.51 35.07 2.01 1.46 0.20 2.97 6.03 -- -- 0.006 0.03 0.15 -- 0.0021 bal.133 0.80 31.48 35.08 2.00 1.47 0.08 3.00 6.01 0.27 -- 0.007 0.16 -- 0.0014 0.0012 bal.134 0.82 31.49 35.09 2.02 1.45 0.09 3.01 6.02 -- 0.35 0.008 0.15 0.06 0.0015 0.0013 bal.comparativealloy135 0.42* 35.10 30.11 5.01 0.52 0.13 5.64 5.00 -- -- -- -- -- -- -- bal.136 2.13* 35.12 30.14 5.00 0.51 0.12 5.60 4.92 -- -- -- -- -- -- -- bal.137 0.75 26.3* 30.17 2.20 0.30 0.05 5.00 4.81 -- -- -- -- -- -- -- bal.138 0.73 40.6* 30.20 2.21 0.29 0.04 4.98 4.80 -- -- -- -- -- -- -- bal.139 0.78 30.24 23.5* 1.63 1.81 1.02 5.39 3.28 -- -- -- -- -- -- -- bal.140 1.05 31.47 30.32 0.60* 0.70 0.10 5.09 3.04 -- -- -- -- -- -- -- bal.141 0.79 30.10 44.60 1.49 4.96* 0.012 4.96 2.97 -- -- -- -- -- -- -- bal.142 0.81 30.09 47.03 1.54 0.014 4.97* 4.93 2.96 -- -- -- -- -- -- -- bal.143 1.04 35.07 35.50 5.03 0.67 0.11 9.88* 2.09 -- -- -- -- -- -- -- bal.144 1.03 35.14 35.47 5.00 0.65 0.10 2.00 10.84* -- -- -- -- -- -- -- bal.priorart alloy145 1.32 25.89 11.04 -- -- -- -- 0.50 1.59 2.00 -- -- -- -- V:0.18 bal.146 1.28 33.92 bal. -- -- -- 3.06 2.98 0.83 0.76 -- -- -- -- Cu:4.94 17.89__________________________________________________________________________ TABLE 4______________________________________VICKERS Charpy AmountHARDNESS impact of Number ofat strength at specific cycle tillroom 900.degree. 1000.degree. room temp. wear .times. occurrencetemp. C. C. kg-m/cm.sup.2 10.sup.-7 of crack______________________________________Alloy of this invention 73 320 161 150 1.80 1.96 >30 74 333 170 154 1.73 1.79 >30 75 380 252 193 1.17 1.21 27 76 331 170 153 1.92 1.72 >30 77 357 184 181 1.63 1.34 >30 78 337 154 148 1.37 1.93 >30 79 360 221 179 2.26 1.67 >30 80 332 168 147 1.88 1.90 >30 81 351 187 179 1.98 1.34 >30 82 340 219 165 2.01 1.47 27 83 371 251 190 1.10 0.98 21 84 360 247 188 1.79 1.39 27 85 389 268 213 1.08 0.96 24 86 377 231 180 1.29 1.37 >30 87 394 259 208 1.20 0.89 24 88 381 254 189 1.48 1.20 >30 89 402 263 213 1.21 0.83 24 90 370 232 178 1.50 1.62 >30 91 376 237 182 1.43 1.50 >30 92 385 253 185 1.28 1.32 30 93 365 238 146 1.96 1.77 >30 94 360 235 144 1.98 1.63 >30 95 358 230 143 2.00 1.52 >30 96 361 237 145 1.93 1.61 >30 97 367 246 153 1.62 1.40 27 98 372 251 167 1.09 1.26 21 99 369 248 155 1.65 1.38 30100 368 247 151 1.66 1.39 >30101 361 237 145 1.99 1.61 >30102 364 241 147 1.70 1.57 >30103 377 253 156 1.51 1.24 30104 362 239 146 2.00 1.60 >30105 365 242 149 1.72 1.55 >30106 379 256 159 1.49 1.18 30107 367 245 150 1.74 1.50 >30108 366 243 148 1.72 1.49 >30109 366 244 149 1.73 1.46 >30110 363 243 147 1.75 1.56 >30111 365 245 148 1.77 1.50 >30112 367 246 149 1.76 1.42 > 30113 361 237 145 1.97 1.58 >30114 365 241 149 1.77 1.52 30115 371 253 156 1.09 1.17 24116 360 236 143 1.96 1.59 >30117 366 243 150 1.70 1.49 27118 373 254 157 1.04 1.12 21119 365 241 146 1.87 1.47 >30120 363 240 146 1.96 1.54 >30121 362 238 145 1.97 1.55 >30122 365 241 147 1.98 1.53 >30123 369 248 153 1.53 1.14 21124 371 251 156 1.34 1.10 21125 365 240 146 1.87 1.41 >30126 368 244 149 1.76 1.33 30127 364 241 145 1.73 1.42 >30128 369 246 147 1.80 1.27 30129 362 240 142 1.96 1.49 >30130 364 242 145 1.91 1.43 >30131 365 244 147 1.93 1.40 >30132 366 245 149 1.90 1.36 >30133 378 254 158 1.90 1.03 >30134 376 250 156 1.93 1.05 >30Comparative alloy135 243 98 83 0.90 3.57 >30136 424 276 223 0.50 0.63 9137 267 101 90 1.94 2.43 >30138 396 220 195 0.74 1.06 6139 287 130 124 0.42 2.61 >30140 251 110 90 0.61 2.63 >30141 428 286 223 0.42 0.64 6142 441 297 248 0.31 0.55 3143 412 271 217 0.30 0.61 6144 419 276 220 0.28 0.64 3prior art alloy145 259 77 64 0.89 3.28 18146 305 143 130 0.43 1.97 3______________________________________

EXAMPLE 3

C-Si-Mn-Cr-Ni-Ti-Al-W-Mo-Fe ALLOY

The alloys shown in EXAMPLE 3 are different from the content of the composition that the alloy include silicon and manganese in comparison with the alloy of EXAMPLE 1.

In EXAMPLE 4, the alloys according to this invention (Nos. 147 to 176), the comparative alloys (Nos. 177 to 187) and the prior art alloys (Nos. 188 to 189) are shown in TABLE 5-1, TABLE 5-2, TABLE 5-3 similar to EXAMPLE 1.

No. 152 of TABLE 5-1 consists essentially of 0.80% by weight of carbon, 0.67% of silicon, 0.11% of manganese, 1.03% of titanium, 0 03% of aluminium, 2.98% of tungsten, 6.21% of molybdenum and the balance iron (% refers to percent by weight).

Furthermore, the alloy of Nos. 166 to 176 include optionally at least one selected from the group consisting of 0.005 to 0.2% of nitrogen, 0.01 to 1.5% of niobium and tantalum, 0.001 to 0.2% of boron and zirconium.

The properties of Nos. 147 to 189 alloys are shown in TABLE 6-1, TABLE 6-2 similar to EXAMPLE 1. For example, No. 152 alloy is shown 366 of Vickers hardness at room temperature, 238 at 900.degree. C., 146 at 1000.degree. C. and 1.98 kg-m/cm.sup.2 of Charpy impact strength at room temperature, 1.79.times.10.sup.-7 of the amount of the specific wear and >30 of the number of the cycle till the occurrence of the crack. Alloys of EXAMPLE 3 are shown the component of the composition and its properties in TABLE 5-1, TABLE 5-2, TABLE 5-3 and TABLE 6-1, TABLE 6-2, respectively.

TABLE 5__________________________________________________________________________ COMPONENT OF COMPOSITION (% by weight) C Si Mn Cr Ni Ti Al W Mo N Nb Ta B Zr Fe__________________________________________________________________________Alloy of thisinvention147 0.558 0.68 0.77 35.1 30.0 0.56 0.11 5.60 5.00 -- -- -- -- -- bal.148 1.28 0.70 0.81 35.2 30.1 0.55 0.10 5.59 4.97 -- -- -- -- -- bal.149 1.86 0.69 0.83 35.0 30.1 0.53 0.11 5.61 4.96 -- -- -- -- -- bal.150 1.03 0.12 0.51 31.5 40.0 1.07 0.04 2.10 5.12 -- -- -- -- -- bal.151 1.01 2.92 0.49 31.4 40.2 1.04 0.05 2.09 5.10 -- -- -- -- -- bal.152 0.80 0.67 0.11 31.7 35.1 1.03 0.03 2.98 6.21 -- -- -- -- -- bal.153 0.79 0.68 1.93 31.6 35.2 1.08 0.02 2.96 6.20 -- -- -- -- -- bal.154 0.70 0.70 0.69 28.4 30.2 0.25 0.06 5.10 4.82 -- -- -- -- -- bal.155 0.69 0.68 0.70 38.1 30.3 0.28 0.02 5.07 4.80 -- -- -- -- -- bal.156 0.76 0.80 0.83 30.2 25.3 1.75 1.00 5.32 3.25 -- -- -- -- -- bal.157 0.77 0.79 0.81 30.1 45.7 1.72 1.09 5.30 3.22 -- -- -- -- -- bal.158 0.81 0.67 0.73 30.2 43.3 0.012 3.86 5.07 2.06 -- -- -- -- -- bal.159 0.80 0.66 0.70 30.1 43.2 4.43 0.05 5.01 2.03 -- -- -- -- -- bal.160 0.82 0.42 0.50 30.1 45.1 3.61 0.011 5.05 2.01 -- -- -- -- -- bal.161 0.80 0.42 0.47 30.0 45.2 0.07 4.41 5.03 2.00 -- -- -- -- -- bal.162 1.03 0.68 0.76 35.1 35.1 0.61 0.22 0.11 7.93 -- -- -- -- -- bal.163 1.00 0.67 0.78 35.0 35.1 0.60 0.24 7.94 1.98 -- -- -- -- -- bal.164 0.98 0.70 0.69 34.1 35.2 0.63 0.17 7.11 0.12 -- -- -- -- -- bal.165 0.96 0.69 0.72 34.0 35.1 0.62 0.16 1.87 8.89 -- -- -- -- -- bal.166 1.06 0.67 0.80 35.0 30.1 0.37 0.10 5.48 5.10 0.083 -- -- -- -- bal.167 1.07 0.77 0.76 34.9 30.2 0.40 0.11 5.47 5.11 -- 0.84 -- -- -- bal.168 1.08 0.78 0.74 34.9 30.1 0.38 0.10 5.50 5.08 -- -- 0.76 -- -- bal.169 1.06 0.79 0.76 35.0 30.3 0.39 0.09 5.51 5.10 -- 0.41 0.40 -- -- bal.170 1.07 0.76 0.77 34.9 30.2 0.38 0.10 5.50 5.11 -- -- -- 0.083 -- bal.171 1.08 0.77 0.78 35.1 30.3 0.37 0.10 5.49 5.09 -- -- -- -- 0.013 bal.172 1.06 0.75 0.79 35.0 30.2 0.39 0.08 5.50 5.12 -- -- -- 0.002 0.004 bal.173 1.07 0.74 0.84 35.1 30.1 0.40 0.10 5.47 5.10 0.009 -- 0.96 -- -- bal.174 1.05 0.73 0.82 34.8 30.2 0.37 0.07 5.46 5.07 0.104 -- -- -- 0.075 bal.175 1.06 0.74 0.80 34.9 30.1 0.39 0.11 5.50 5.09 0.008 0.69 -- 0.071 -- bal.176 1.05 0.75 0.78 35.0 30.3 0.38 0.10 5.48 3.10 0.069 0.48 -- 0.015 0.104 bal.COMPARATIVEALLOY177 0.41* 0.69 0.80 35.1 30.1 0.50 0.10 5.57 4.98 -- -- -- -- -- bal.178 2.36* 0.70 0.78 35.0 30.0 0.51 0.09 5.56 4.99 -- -- -- -- -- bal.179 1.04 4.23* 0.51 31.5 40.2 1.03 0.04 2.10 5.11 -- -- -- -- -- bal.180 0.80 0.67 3.03* 31.7 35.1 1.09 0.03 2.98 6.18 -- -- -- -- -- bal.181 0.69 0.71 0.73 26.1* 30.1 0.28 0.05 5.09 4.89 -- -- -- -- -- bal.182 0.70 0.70 0.71 41.3* 30.2 0.30 0.03 5.08 4.85 -- -- -- -- -- bal.183 0.80 0.77 0.84 30.1 22.4* 1.78 1.04 5.31 3.27 -- -- -- -- -- bal.184 0.79 0.68 0.73 30.1 43.2 5.13* 0.06 5.00 2.04 -- -- -- -- -- bal.185 0.79 0.41 0.50 30.1 45.3 0.08 5.26* 5.01 2.02 -- -- -- -- -- bal.186 1.01 0.70 0.76 35.1 35.2 0.62 0.28 9.04* 1.99 -- -- -- -- -- bal.187 0.98 0.71 0.70 34.0 35.0 0.61 0.17 1.86 10.03* -- -- -- -- -- bal.prior art alloy188 1.32 1.59 2.00 25.9 11.0 -- -- -- 0.50 -- -- -- -- V: bal.189 1.28 0.83 0.76 34.0 bal. -- -- 3.06 2.98 -- -- -- -- Cu: 17.9__________________________________________________________________________ TABLE 6______________________________________VICKERS Charpy AmountHARDNESS impact of Number ofat strength at specific cycle tillroom 900.degree. 1000.degree. room temp. wear .times. occurrencetemp. C. C. kg-m/cm.sup.2 10.sup.-7 of crack______________________________________ALLOY OF THIS INVENTION147 318 160 149 1.81 1.96 >30148 331 168 155 1.76 1.73 >30149 379 253 192 1.23 0.98 27150 374 235 181 1.39 1.52 >30151 383 251 183 1.31 1.37 30152 366 238 146 1.98 1.79 >30153 357 230 141 2.01 1.53 >30154 332 171 154 1.93 1.72 >30155 360 187 183 1.52 1.34 30156 338 156 150 1.34 1.91 >30157 360 221 179 2.26 1.63 >30158 356 235 144 1.96 1.50 30159 369 251 192 1.20 0.96 27160 350 231 140 1.99 1.54 >30161 385 261 200 1.14 0.93 24162 378 238 183 1.26 1.29 30163 394 263 210 1.20 0.89 24164 382 255 190 1.48 1.24 30165 402 264 213 1.16 0.86 24166 356 184 148 1.90 1.70 >30167 348 218 185 1.38 1.46 >30168 350 215 180 1.51 1.49 >30169 362 234 189 1.36 1.10 >30170 351 207 178 1.40 1.02 27171 346 192 173 1.31 1.08 27172 364 208 186 1.26 1.00 24173 379 237 187 1.30 0.99 27174 393 270 202 1.08 0.95 21175 373 215 192 1.29 1.02 24176 403 282 214 1.20 0.86 21COMPARATIVE ALLOY177 248 97 83 0.99 3.83 >30178 421 276 224 0.53 0.70 12179 420 257 200 0.75 1.03 9180 324 148 123 2.09 1.14 >30181 267 100 89 1.98 2.53 >30182 394 219 192 0.81 1.12 6183 286 128 125 0.47 2.68 >30184 418 279 218 0.56 0.81 6185 427 286 238 0.47 0.90 3186 413 271 218 0.44 0.66 6187 418 276 221 0.36 0.71 3prior art alloy188 259 77 64 0.89 3.28 18189 305 143 130 0.43 1.97 3______________________________________

EXAMPLE 4

C-Si-Mn-Cr-Ni-Co-W-Mo-Ti-Al-Fe ALLOY

The alloys shown in EXAMPLE 4 are different from the content of the composition that the alloys include one to 8% by weight in comparison with alloys of EXAMPLE 3. Alloys of this invention (Nos. 192 to 222), comparative alloys (Nos. 224 to 235), and prior art alloys (Nos. 190 to 191) are shown the component of the composition in TABLE 7-1, TABLE 7-2, and TABLE 7-3. The properties of alloys are shown in TABLE 8-1 and TABLE 8-2.

No. 199 alloy consists essentially of 0.70% by weight of carbon, 0.68% of silicon, 0.70% of manganese, 28.97% of chromium, 30.12% of nickel, 2.15% of cobalt, 5.06% of tungsten, 4.80% of molybdenum, 0.23% of titanium, 0.05% of aluminium, and the balance iron (% refers to percent by weight).

Furthermore, alloys of Nos. 224 to 235 include optionally at least one selected from the group consisting of 0.005 to 0.2% of nitrogen, 0.01 to 1.5% of niobium and tantalum, and 0.001 to 0.2% of boron and zirconium.

The properties of Nos. 190 to 235 alloys are shown in TABLE 8-1 and TABLE 8-2 similar to EXAMPLE 1.

For example, No. 199 alloy is shown 336 of Vickers hardness at room temperature, 175 at 900.degree. C., 158 at 1000.degree. C. and 1.87 k-gm/cm.sup.2 of Charpy impact strength at room temperature 1.67.times.10.sup.-7 of the amount of the specific wear, and >30 of the number of the cycle till the occurrence of the crack

No. 199 in EXAMPLE 4 include 2.15% by weight of cobalt in comparison with alloy having similar composition of No. 154 in EXAMPLE 3. No. 154 alloy is shown 332 of Vickers hardness at room temperature, 171 at 900.degree. C., 154 at 1000.degree. C. Furthermore No. 154 alloy shows 1.93 kg-m/cm.sup.2 of Charpy impact strength at room temperature, 1.72.times.10.sup.-7 of the amount of the specific wear, >30 of the number of the cycle till the occurrence of the crack. The component of the composition and its properties are shown in TABLE 7-1, TABLE 7-2, TABLE 7-3 and TABLE 8-1, TABLE 8-2, respectively.

TABLE 7__________________________________________________________________________ COMPONENT OF COMPOSITION (% by weight) C Si Mn Cr Ni Co W Mo Ti Al N Nb Ta B Zr Cu V Fe__________________________________________________________________________priorart alloy190 1.32 1.59 2.00 25.89 11.04 -- -- 0.50 -- -- -- -- -- -- -- -- 0.18 bal.191 1.28 0.83 0.76 33.92 bal. -- 3.06 2.98 -- -- -- -- -- -- -- 4.94 -- 17.89ALLOY OFTHISINVENTION192 0.56 0.70 0.79 35.03 30.10 5.01 5.56 4.94 0.51 0.10 -- -- -- -- -- -- -- bal.193 1.22 0.71 0.83 35.00 30.09 5.03 5.62 4.86 0.50 0.09 -- -- -- -- -- -- -- bal.194 1.85 0.15 0.82 35.05 30.08 5.12 5.59 4.80 0.53 0.11 -- -- -- -- -- -- -- bal.195 1.01 1.60 0.49 31.57 40.12 5.04 2.04 5.11 1.04 0.04 -- -- -- -- -- -- -- bal.196 1.00 2.70 0.46 31.50 40.13 5.00 2.01 5.14 1.03 0.05 -- -- -- -- -- -- -- bal.197 0.78 0.65 0.11 31.60 35.07 2.00 3.00 6.15 1.02 0.04 -- -- -- -- -- -- -- bal.198 0.80 0.66 1.70 31.59 35.06 2.03 2.99 6.16 1.00 0.06 -- -- -- -- -- -- -- bal.199 0.70 0.68 0.70 28.97 30.12 2.15 5.06 4.80 0.23 0.05 -- -- -- -- -- -- -- bal.200 0.71 0.67 0.71 37.98 30.15 2.16 5.00 4.81 0.20 0.01 -- -- -- -- -- -- -- bal.201 0.75 0.79 0.82 30.14 25.10 1.59 5.31 3.23 1.74 1.02 -- -- -- -- -- -- -- bal.202 0.74 0.78 0.81 30.12 47.93 1.57 5.29 3.25 1.70 1.10 -- -- -- -- -- -- -- bal.203 1.02 0.68 0.80 31.50 30.24 1.60 5.07 2.99 0.59 0.10 -- -- -- -- -- -- -- bal.204 1.03 0.71 0.79 31.51 30.25 7.91 5.09 2.98 0.60 0.09 -- -- -- -- -- -- -- bal.205 1.02 0.70 0.80 34.97 35.00 5.01 0.52 7.95 0.57 0.10 -- -- -- -- -- -- -- bal.206 1.01 0.69 0.81 34.94 35.02 5.04 7.96 2.00 0.59 0.11 -- -- -- -- -- -- -- bal.207 0.99 0.67 0.70 34.01 35.02 4.96 7.00 0.87 0.61 0.09 -- -- -- -- -- -- -- bal.208 0.98 0.69 0.69 34.04 35.00 4.94 2.09 8.01 0.60 0.08 -- -- -- -- -- -- -- bal.209 0.81 0.80 0.79 30.12 42.11 1.60 5.00 2.99 0.91 0.09 -- -- -- -- -- -- -- bal.210 0.82 0.77 0.78 30.11 42.10 1.51 5.03 2.98 3.34 0.07 -- -- -- -- -- -- -- bal.211 0.80 0.80 0.79 30.08 45.01 1.53 5.04 3.04 0.52 1.57 -- -- -- -- -- -- -- bal.212 0.81 0.78 0.76 30.07 45.03 1.51 5.02 3.01 0.018 3.31 -- -- -- -- -- -- -- bal.213 1.07 0.69 0.81 34.99 30.08 5.00 5.53 4.97 0.31 0.08 0.110 -- -- -- -- -- -- bal.214 1.06 0.67 0.80 34.97 30.06 5.03 5.54 4.99 0.33 0.06 -- -- 0.71 -- -- -- -- bal.215 1.09 0.68 0.79 34.99 30.07 5.01 5.50 5.00 0.30 0.08 -- 0.80 -- -- -- -- -- bal.216 1.08 0.78 0.77 34.96 30.04 5.00 5.53 4.99 0.32 0.08 -- 0.31 0.44 -- -- -- -- bal.217 1.09 0.72 0.79 35.03 30.08 5.04 5.51 4.96 0.31 0.07 -- -- -- 0.089 -- -- -- bal.218 1.07 0.69 0.77 34.99 30.09 5.01 5.50 4.99 0.26 0.09 -- -- -- -- 0.102 -- -- bal.219 1.06 0.70 0.78 34.96 30.10 5.00 5.49 4.98 0.31 0.07 -- -- -- 0.039 0.055 -- -- bal.220 1.08 0.71 0.80 35.01 30.11 5.02 5.51 5.01 0.29 0.09 0.069 1.09 -- -- -- -- -- bal.221 1.09 0.69 0.70 35.00 30.07 5.02 5.53 5.00 0.30 0.09 0.082 -- -- 0.092 -- -- -- bal.222 1.07 0.68 0.74 35.02 30.08 5.01 5.50 5.01 0.32 0.08 -- -- 0.92 -- 0.087 -- -- bal.223 1.09 0.70 0.77 35.00 30.10 5.03 5.49 5.03 0.30 0.09 0.072 0.57 0.30 0.054 0.045 -- -- bal.COMPAR-ATIVEALLOY224 0.28* 0.69 0.78 35.00 30.17 5.06 5.57 4.96 0.50 0.08 -- -- -- -- -- -- -- bal.225 2.06* 0.71 0.80 34.98 30.12 5.11 5.59 4.90 0.52 0.08 -- -- -- -- -- -- -- bal.226 1.02 4.23* 0.51 31.58 40.10 4.97 2.01 5.13 1.01 0.05 -- -- -- -- -- -- -- bal.227 0.71 0.66 3.08* 31.55 35.04 2.05 3.00 6.18 0.99 0.07 -- -- -- -- -- -- -- bal.228 0.73 0.68 0.71 25.01* 30.03 2.11 5.04 4.79 0.25 0.06 -- -- -- -- -- -- -- bal.229 0.70 0.67 0.70 40.89* 30.10 2.12 5.06 4.80 0.21 0.04 -- -- -- -- -- -- -- bal.230 0.73 0.80 0.80 30.10 20.01* 1.56 5.30 3.01 1.68 1.02 -- -- -- -- -- -- -- bal.231 1.00 0.71 0.81 31.54 30.06 0.31* 5.09 2.97 0.57 0.09 -- -- -- -- -- -- -- bal.232 1.02 0.73 0.78 34.97 35.01 5.02 9.97* 2.01 0.61 0.10 -- -- -- -- -- -- -- bal.233 1.00 0.70 0.68 34.03 35.03 4.96 2.08 9.88* 0.58 0.08 -- -- -- -- -- -- -- bal.234 0.80 0.76 0.79 30.09 42.03 1.50 5.01 2.96 4.00* 0.07 -- -- -- -- -- -- -- bal.235 0.79 0.81 0.78 30.10 45.00 1.56 5.03 3.06 0.51 4.02* -- -- -- -- -- -- -- bal.__________________________________________________________________________ TABLE 8______________________________________VICKERS Charpy AmountHARDNESS impact of Number ofat strength at specific cycle tillroom 900.degree. 1000.degree. room temp. wear .times. occurrencetemp. C. C. kg-m/cm.sup.2 10.sup.-7 of crack______________________________________prior art alloy190 259 77 64 0.89 3.28 18191 305 143 130 0.43 1.97 3ALLOY OF THIS INVENTION192 322 163 152 1.78 1.90 >30193 336 172 158 1.70 1.71 >30194 383 256 196 1.14 0.94 27195 379 239 184 1.33 1.47 >30196 387 254 187 1.26 1.30 30197 369 241 149 1.93 1.72 >30198 360 233 145 1.99 1.48 >30199 336 175 158 1.87 1.67 >30200 362 190 187 1.41 1.22 30201 341 160 153 1.26 1.80 >30202 364 226 183 2.13 1.50 >30203 338 174 150 1.82 1.83 >30204 357 192 183 1.95 1.29 >30205 381 240 186 1.21 1.26 30206 398 264 213 1.18 0.87 24207 386 259 194 1.42 1.13 30208 406 268 218 1.13 0.81 24209 341 218 166 2.08 1.51 >30210 370 252 193 1.24 1.00 24211 362 248 189 1.81 1.43 30212 386 263 201 1.18 0.98 27213 381 253 166 1.24 1.00 27214 354 218 183 1.38 1.42 >30215 351 221 189 1.26 1.40 30216 366 237 193 1.38 1.08 >30217 354 210 182 1.31 1.00 30218 356 207 188 1.23 1.02 24219 368 211 189 1.21 0.96 24220 384 242 190 1.28 0.98 27221 394 271 203 1.19 0.94 24222 377 219 196 1.24 1.00 24223 407 286 218 1.17 0.80 21COMPARATIVE ALLOY224 250 100 85 0.93 3.51 >30225 426 278 226 0.51 0.67 12226 424 260 203 0.73 1.00 9227 328 153 127 2.03 1.04 >30228 270 104 92 1.96 2.41 >30229 398 223 197 0.76 1.02 6230 290 133 128 0.40 2.55 >30231 254 114 92 0.64 2.67 >30232 415 274 220 0.34 0.63 6233 421 279 223 0.30 0.69 3234 417 278 216 0.58 0.83 6235 426 285 236 0.49 0.92 3______________________________________

ABILITY OF INDUSTRIAL UTILITY

The alloy of this invention are employed for the guide shoe included the pierced billet used in a hot rolling apparatus for fabricating seamless steel pipe due to improve in the thermal and wear resistance, toughness at elevated temperatures.

The alloy of this invention have the industrial utilizable properties and the extremely long life and the stability. Furthermore, the alloy according to this invention is applied widely to employing for the build-up weld.

Claims

1. A thermal and wear resistant, tough alloy at elevated temperatures consisting essentially of 0.65 to 1.9% by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% of tungsten, 0.1 to 9% by weight of molybdenum and the balance iron and incidental impurities, the alloy including up to 3% by weight of silicon up to 2% by weight of manganese, up to 8% by weight of cobalt, up to 0.2% by weight of nitrogen, up to 1.5% by weight of niobium and tantalum and up to 0.2% by weight of boron and zirconium.

2. The thermal and wear resistant, tough alloy at elevated temperatures consisting essentially of 0.65 to 1.9% by weight of carbon, 28 to 319% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum and the balance iron and incidental impurities.

3. The alloy as defined in claim 2, wherein further said alloy is included 0.005 to 0.2% by weight of nitrogen.

4. The alloy as defined in claim 2, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

5. The alloy as defined in claim 2, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

6. The alloy as defined in claim 3, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

7. The alloy as defined in claim 3, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

8. The alloy as defined in claim 4, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

9. The alloy as defined in claim 6, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

10. The thermal and wear resistant, tough alloy at elevated temperatures consisting essentially of 0.65 to 1.9% by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum, 0.1 to 3% by weight of silicon and the balance iron and incidental impurities.

11. The alloy as defined in claim 10, wherein further said alloy is included 0.005 to 0.2% by weight of nitrogen.

12. The alloy as defined in claim 10, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

13. The alloy as defined in claim 10, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

14. The alloy as defined in claim 11, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

15. The alloy as defined in claim 11, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

16. The alloy as defined in claim 12, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

17. The alloy as defined in claim 14, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

18. The thermal and wear resistant, tough alloy at elevated temperatures consisting essentially of 0.7 to 1.9% by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum, 0.1 to 2% by weight of manganese and the balance iron and incidental impurities.

19. The alloy as defined in claim 18, wherein further said alloy is included 0.005 to 0.2% by weight of nitrogen.

20. The alloy as defined in claim 18, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

21. The alloy as defined in claim 18, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

22. The alloy as defined in claim 19, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

23. The alloy as defined in claim 19, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

24. The alloy as defined in claim 20, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

25. The alloy as defined in claim 22, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

26. The thermal and wear resistant, tough alloy according to claim 1 consisting essentially of 0.65 to 1.9% by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum, 1 to 8% by weight of cobalt and the balance iron and incidental impurities.

27. The alloy as defined in claim 26, wherein further said alloy is included 0.005 to 0.2% by weight of nitrogen.

28. The alloy as defined in claim 26, wherein further said alloy are included at least one selected from the group consisting 0.01 to 1.5% by weight of niobium and tantalum.

29. The alloy as defined in claim. 26, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

30. The alloy as defined in claim 27, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

31. The alloy as defined in claim 27, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

32. The alloy as defined in claim 28, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

33. The alloy as defined in claim 30, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

34. The thermal and wear resistant, tough alloy according to claim 1 consisting essentially of 0.65 to 1.9% by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum, 0.1 to 3% by weight of silicon, 1 to 8% by weight of cobalt and the balance iron and incidental impurities.

35. The alloy as defined in claim 34, wherein further said alloy is included 0.005 to 0.2% by weight of nitrogen.

36. The alloy as defined in claim 34, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

37. The alloy as defined in claim 34, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

38. The alloy as defined in claim 35, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

39. The alloy as defined in claim 35, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

40. The alloy as defined in claim 36, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

41. The alloy as defined in claim 38, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

42. The thermal and wear resistant, tough alloy according to claim 1 consisting essentially of 0.65 to 1.9% by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum, 0.1 to 2% by weight of manganese, 1 to 8% by weight of cobalt and the balance iron and incidental impurities.

43. The alloy as defined in claim 42, wherein further said alloy is included 0.005 to 0.2% by weight of nitrogen.

44. The alloy as defined in claim 42, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

45. The alloy as defined in claim 42, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

46. The alloy as defined in claim 43, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

47. The alloy as defined in claim 43, wherein further said alloy are included at least one selected from the group consisting 0.001 to 0.2% by weight of boron and zirconium.

48. The alloy as defined in claim 44, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

49. The alloy as defined in claim 46, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

50. The thermal and wear resistant, tough alloy according to claim 1 consisting essentially of 0.65 to 1.9 by weight of carbon, 28 to 39% by weight of chromium, 25 to 49% by weight of nickel, 0.01 to 4.5% by weight of titanium, 0.01 to 4.5% by weight of aluminium, 0.1 to 8% by weight of tungsten, 0.1 to 9% by weight of molybdenum, 0.1 to 3% by weight of silicon, 0.1 to 2% by weight of manganese, 1 to 8% by weight of cobalt and the balance iron and incidental impurities.

51. The alloy as defined in claim 50, wherein further said alloy is included 0.005 to 0.2% by weight of nitrogen.

52. The alloy as defined in claim 50, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

53. The alloy as defined in claim 50, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

54. The alloy as defined in claim 51, wherein further said alloy are included at least one selected from the group consisting of 0.01 to 1.5% by weight of niobium and tantalum.

55. The alloy as defined in claim 51, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

56. The alloy as defined in claim 52, wherein further said alloy are included at least one selected the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

57. The alloy as defined in claim 54, wherein further said alloy are included at least one selected from the group consisting of 0.001 to 0.2% by weight of boron and zirconium.

58. The alloy as defined in claim 1 wherein the amount, when present, of silicon is 0.1 to 3%, manganese is 0.1 to 2% cobalt is 1 to 8%, nitrogen is 0.05 to 0.2% niobium and tantalum is 0.01 to 1.5%, and boron and zirconium are 0.001 to 0.2%.